• 제목/요약/키워드: strict topology

검색결과 14건 처리시간 0.023초

Topology-Aware Fanout Set Division Scheme for QoS-Guaranteed Multicast Transmission

  • Kim, Kyungmin;Lee, Jaiyong
    • Journal of Communications and Networks
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    • 제15권6호
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    • pp.614-634
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    • 2013
  • The proliferation of real-time multimedia services requires huge amounts of data transactions demanding strict quality-of-service (QoS) guarantees. Multicast transmission is a promising technique because of its efficient network resource utilization. However, high head-of-line (HOL) blocking probability and lack of service-specific QoS control should be addressed for practical implementations of multicast networks. In this paper, a topology aware fanout set division (TAFD) scheme is proposed to resolve these problems. The proposed scheme is composed of two techniques that reduce HOL blocking probability and expedite packet delivery for large-delay branches regarding multicast tree topology. Since management of global topology information is not necessary, scalability of the proposed scheme is guaranteed. Mathematical analysis investigates effects of the proposed scheme and derives optimal operational parameters. The evaluation results show that the TAFD scheme achieves significant delay reduction and satisfies required delay bounds on various multicast networks.

낮은 출력 리플을 갖는 연료전지를 이용한 리튬폴리머 전지용 비절연형 승압 충전기의 설계 (Design of the Non-Isolated Fuel Cell Boost Charger for the Lithium Polymer Battery with Low Output Ripple)

  • 트란반롱;최우진
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2013년도 전력전자학술대회 논문집
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    • pp.182-183
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    • 2013
  • In the design of the fuel cell charger, it is important to find out the suitable topology and to design the converter to guarantee the performance of the fuel cell as well as the battery. Most of the chargers developed so far have used step-down converters. However, since the small fuel cell stack can only generate a low voltage, it is required to use the step-up converter to charge the battery. In this paper, a modified non-isolated boost charger topology for the Proton Exchange Membrane Fuel Cell (PEMFC) is proposed to meet the strict ripple requirements for the battery charge and its control method by using PI controller is detailed. The feasibility of the proposed topology and its control method is then verified by the experiments.

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Configuration of Mail Delivery System Based on Reinforcement Learning

  • Morishita, Soichiro;Hiraoka, Kazuyuki;Kobayashi, Hidetsune;Mishima, Taketoshi
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -2
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    • pp.830-833
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    • 2002
  • To solve the internal security problem such as human error and bad faith, the automation of computer system management is significant. For this purpose, we focus attention in the automation of Mail Delivery Service. Today, requirement for reliable mail delivery system becomes larger and larger. However, existing systems are too strict about their configuration. Hence, we propose the method based on Reinforcement Learning (RL) to achieve proper MX record ordering. A measure on validity of the design of system, such as network topology number of servers and so on, is also obtained as side benefit. In order to verify the usability of the presented method, we did on a small model of mail delivery system. As a result, we show that RL is available for determination of the proper MX record ordering. Additionally, we suggest that it is also available for comparing validity of setting of MTA and the network design.

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Radiator cooling fan용 스위치드 릴럭턴스 전동기 및 토폴로지에 관한 연구 (A Study on Switched Reluctance Motor and Converter topology for Radiator Cooling Fan)

  • 정동효;윤용호;한대희;이태원;원충연
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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    • pp.866-871
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    • 2003
  • In automobile, the introduction of electronically commutated motors has been accompanied by a proliferation of electronic devices. With this proliferation of electronic devices, an emphasis has been placed on EMC issues. This paper is proposed to use SRM as a radiator cooling fan in automotive applications. To drive SRM, Energy efficient C-dump converter is applied. It is verified more efficient than other converters through simulation and experiments. And also SRM is valid automotive applications that have strict EMC standards. It is compared SRM with BLDC and DC motor by experiments.

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주상복합아파트의 공적공간에 관한 연구 (A Study on the Public Space of Mixed-Use Housing)

  • 장경수
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2005년도 추계학술발표대회 논문집
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    • pp.183-186
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    • 2005
  • The purpose of this study is to actualize the planning method of the Mixed-use Housing. Enter in 2000 years, contruction of Mixed-use Housing is rapidly increasing with acrovill and tower palace as its starting point. Mixed-use Housing is topology that mix function of residential and business and commercial facilities by kind of mixed-use development. And, Mixed-use Housing which is located in busy urban commercial strict should meet the demand not only as functional city. And it is a type of urban housing that located in busy urban commercial district demands function of residential. As for locational situation and types of public space researched and analyzed in this thesis, those space were left alone with short analyzation on main consumers level as well as short recognition of public space for all of the six combined facilities of dewelling and commercing

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MAC layer based cross-layer solutions for VANET routing: A review

  • Nigam, Ujjwal;Silakari, Sanjay
    • International Journal of Computer Science & Network Security
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    • 제21권12spc호
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    • pp.636-642
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    • 2021
  • Vehicular Ad hoc Networks (VANET's) are gaining popularity in research community with every passing year due to the key role they play in Intelligent Transportation System. Their primary objective is to provide safety, but their potential to offer a variety of user-oriented services makes them more attractive. The biggest challenge in providing all these services is the inherent characteristics of VANET itself such as highly dynamic topology due to which maintaining continuous communication among vehicles is extremely difficult. Here comes the importance of routing solutions which traditionally are designed using strict layered architecture but fail to address stringent QoS requirements. The paradigm of cross-layer design for routing has shown remarkable performance improvements. This paper aims to highlight routing challenges in VANET, limitations of single-layer solutions and presents a survey of cross-layer routing solutions that utilize the information from the MAC layer to improve routing performance in VANET.

새로운 시분할 다중 제어 기법을 이용한 소프트 스위칭 다중 출력 충전기 (Soft Switching Multiple Output Charger By Using Novel Time Division Multiple Control Technique)

  • 트란반롱;최우진
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2014년도 전력전자학술대회 논문집
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    • pp.191-192
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    • 2014
  • Multiple output converters (MOCs) are widely used for applications which require various levels of the output voltages due to their benefits in cost, volume, and efficiency. However, most of the MOCs developed so far can regulate only one output tightly and require as many secondary windings in the transformer as the number of the outputs. In this paper, a novel Time Division Multiple Control (TDMC) method to regulate all the outputs in high precision is proposed and applied for the multiple output battery charger based on the phase shift full bridge topology to charge a multiple number of batteries at one time. The proposed converter can charge three different kinds of batteries or same kind of batteries in different state of charges (SOCs) by using constant current/constant voltage (CC/CV) charge mode independently. At the same time it can provide an even degree of tight regulation for each output to satisfy the strict ripple requirement of the battery. The validity and feasibility of the proposed method are verified through the experiments.

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DiffServ 기반 네트워크에서의 실시간 트래픽 서비스 (Real-time traffic service in network with DiffServ)

  • 정진우
    • 한국통신학회논문지
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    • 제32권1B호
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    • pp.53-60
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    • 2007
  • 본 연구에서는 Diffserv 기반의 네트워크, 특히 그 중에서도 트리구조를 가지는 네트워크에서의 지연시간에 대해서 연구하였다. 이러한 네트워크에서의 지연시간 최대치를 구하는 수식을 구하였고, 특히 기존에 알려진 바와는 달리 트리구조의 네트워크에서는 네트워크 utilization과는 상관없이 최대치가 항상 존재함을 보였다. 지연시간 최대치의 특성은 다음과 같이 표현된다. 네트워크 utilization이 큰 경우 네트워크내의 최대 hop count의 제곱에 비례하며, 네트워크 utilization이 작은 경우는 최대 hop count에 비례한다. 이러한 결과를 바탕으로 실제 Metro Ethernet Network과 같은 대규모 네트워크의 경우에서 DiffServ를 이용하여 실시간 트래픽 전송이 가능하다는 것을 보였다.